Dimethylpolysiloxane and methylphenyl-polysiloxane are colorless transparent liquids whose viscosity can be varied over a wide range depending on production conditions, including from low viscosity liquid having a low molecular weight to highly viscous raw rubber-like materials, and what is more, they are excellent in heat resistance, cold resistance, chemical resistance, water resisting property, lubricity, water repelling property, mold releasing facility, defoamability, electric characteristics, and so on. Consequently, they have many industrial uses, e.g., as lubricating oil, a lustering agent, damping oil, electric insulating oil, oil to be injected and impregnated, a cosmetic component, a mold releasing agent, a defoaming agent, an agent for water-repellent treatment, a textile treating agent, an additive for coating materials, an additive for plastics, and so on.
In most of those cases, dimethylpolysiloxane or methyl-phenylpolysiloxane has been used independently. However, each of these polysiloxanes is not only poor in boundary lubricity and durability but also small in surface energy because of its weakness in intermolecular force. Therefore, each suffers from disadvantages of being poor in, e.g., finishing and coating abilities. As one of the methods for obviating such disadvantages, it is known to impart various functions to each polysiloxane by introducing organic groups other than methyl or phenyl group, e.g., polyoxyalkylene groups, alkyl groups containing two or more carbon atoms, ester groups, aralkyl groups, etc., into the siloxane chain.
According to this method, dimethylpolysiloxane and methylphenyl-polysiloxane can acquire new characteristics depending on the substituent groups introduced thereinto, but the introduction of substituent groups causes deterioration of properties inherent in these polysiloxane, e.g., heat resistance, chemical resistance, water-repelling ability, mold releasing facility, electric characteristics, etc.
As another method for removing defects of dimethylpolysiloxane and methylphenyl-polysiloxane, it is also known to mix them with waxes, fats and oils, organic polymers, or so on. However, polysiloxane polymers have a small value of solubility parameter, so the method has a serious defect in that, since compatiblity with general waxes, fats and oils, organic polymers and so on is difficult, the resulting mixtures lack stability.
As a result of concentrating our energies on a solution for the above-described problems, it has now been found that a remarkably favorable result can be obtained by copolymerizing, with stirring, a dimethylsiloxane(meth) acrylate macromonomer and one or more of a vinylic polymerizable monomer, which is able to copolymerize with said macromonomer, in the presence of either dimethylpolysiloxane or methylphenyl-polysiloxane, organic waxes and a radical producing agent, thus achieving this invention.